They take the roster spots of shortstop Marwin Gonzalez, who was optioned to Oklahoma City on Monday, and left-hander Wade LeBlanc, who was designated for assignment.

Wallace started for the Astros on opening day but was sent to Oklahoma City after going 1 for 24 with 17 strikeouts and a .042 batting average in seven games. He is hitting .326 with 11 homers and 37 RBIs in 59 games for Oklahoma City.

Elmore, who has played three games for Houston this season, has spent most of the year in Triple-A. He is hitting .300 with five homers, 30 RBIs and 16 stolen bases for the RedHawks.